SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7770786c93c4797549bfe871ad2c2c1973fe8e8800afed98b65387cfc612c585' 
  AND token = 'THP3+wnvjCiUL2nqxA7a4C9/MisDvdzqrMc13dzVrgg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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