SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8eadaaaf4393f3ed1b6b617e71914fc489d2f5fe4574b96c3054792eab87389c' 
  AND token = 'HqgRCoM3rZkD2OKQrzovn/anKSmyh1NLEo9O1C1/08k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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