SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e5fed6b90157930586b31343ed26b1fa21fad451bb35665192d5c6a716d445c4' 
  AND token = '1JD9nXdRDUnUwHAW5/1CLabtCCo9poMRF4Mvy+ldGiY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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