SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '54be41f2ebc5957ffafed8240a87b508f18d115e06303e958a3353a6cc9668e1' 
  AND token = 'FJlDnGmsZ2/ns+6kydvCLyQnkTyi20W1a67VLWtD2xM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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