SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7c6439dd9741b091eec3f2db4d56da9e498c263e51cc3700cc80946bfb7c9a8f' 
  AND token = 'NUCOZAivkrVjvqQoEplTOu6NOD38WomQJt913ctsiv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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