SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd94f3b67f12ffa6612133332dc3f8c26c01b2b88484f208a34eb7d5435dcb259' 
  AND token = 'ScMs+NCU7upPFv9gFLU7PNVl0BtOx/9zLGb8JBUXHUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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