SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '432c4589dabd729b41bc8476fb0a4156ade4e9c12ee09eec577f0d4ee7416e8f' 
  AND token = 'QlAa83ymjty5jZDUO36ydfApqppZ4PG7UTUtQKoQPCM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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