SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a1f5ed50248b790722b0bd045dc646dc2eec812094fb388f33ffe4016bbca20' 
  AND token = 'zCxm9b5J79ApbClKkxJN2NkONjlzCcoQSanwD4hJnK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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