SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf6805f086bb70b81d8de0333a8789465fbf08adccde5874732a77e07bd1d850' 
  AND token = 'Z5nw81qjBeojc2Ml+IneHqsMHNVqT7zF7qbBzRW266M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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