SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfe8e5fb12d063e25d754e0783e28cc88423518651f57908130ee23001ba6650' 
  AND token = 'd4x9BcAPUlun9MceU+LwCKG626S+D8NtKhoFvhoPLb8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}