SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b5e1a9717282527da114b4301cc307388ab3b35799a1d2e30de118bab77263d' 
  AND token = 'oebpgUKobCBCFEuXgY+6j+BFIaotkD565rLZXRLFD10=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}