SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '928aa7a9624c8513ef076850909a21c7b4ff2dc2b448f963e24e85bc627e3ffd' 
  AND token = 'flaDtfhPgxCX/YMjjM83XYpqJ0RodJ8KqRlNlOnDKPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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