SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8a3bb58a9e702899f3d96fe8d76a5a62b7b0a4c92ed7cb04f49d14c8a92733a' 
  AND token = '+owl0R/At6hubmqbhfEIG9fW8PcEsnA+MPjZKTJzwxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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