SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a28e937e5f518effbcb67f1aea1c2f00464a5b286edbf319fb3093fadfb0237' 
  AND token = '2wVXWOmezBpBPknDw1GHErGt5fR3c47s1EkcLBmgcKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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