SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77f6932701a11bec8ea1f1e6edc7b0216177fc1715329cc4cfec1265f5ad580e' 
  AND token = 'qKfqH9oBpqAEhjlq3AtHVCR0d6gnNRjA+kSpzfycVgs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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