SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69f0b7826d334dc56cf027458eceab34560ad1f782965cf819bee75399bdc5bc' 
  AND token = 'JVffDVU3ZqBObJMytOpV4it+d55WJyW5eIZtzvQlwV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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