SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f882ac52a570858ec21f7df07043b4e326622568048e0c94fd622b72c422339e' 
  AND token = 'aIfOg0krk0XclQjCG6JSK7NPG5sCR+yCVyVafxSiAoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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