SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a82313889c12e853da37f6981616c32d3cc2028b31181bd5355c381bc70b9dca' 
  AND token = '8XQ5KTTDDfhmgRBcvYkup84JttHYqcVocsUGA3Tj0J8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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