SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ffe2749972e8602371fdeb972b63c0532485be3f251b58c017edf273d1e2b1ec' 
  AND token = 'JaFgUKwmZVfuxCvWSe2KQLbozjnvmnVIZkW2iY5Vazs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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