SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd59b2246ecbc29372db14c3a260179548f310cf31e8cfd388f7429c7925491b5' 
  AND token = '1nNBfISOPc43BSjoiRTt3u5oADtOXjssHqbWqPBsrfU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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