SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf4387c288ed440c937bfd769708ce4f0ea9b946cace44a03922663b2c8899f7' 
  AND token = 'GeSvp6qVEjdIRBvG/IYoPttwrtGQTbMnt4lcxNjzSq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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