SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '638679f92ad766da57fc04339c7476098d63e625c601ae8b78d6917d2266dd93' 
  AND token = 'hTmSsvxipucDDrwlGPhJ/roN3VEvkyeZNsEfdcmxCPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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