SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed6532cf1c3022f238b928c6321058fb610b4b8bc217ad5ae2ca02dc65580870' 
  AND token = 'TgegsYYkVQxlYaIvxRNoa1qKjrSoEe0IawWme9lQpr8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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