SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '673a445bc9d47bd28899455a8648c41687f76684466265741a4aad5d2eab294d' 
  AND token = 'AORMRpugn6W45M9To2av4DtGpq+9BrRrSlGcjpFHiuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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