SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '736638f67226065f581003f5340b672eb1e0a95875c94c263e56b54dfbdd5426' 
  AND token = '/dAtjagrERMlkbYj/iBc1/lLGTVZS1/pGPv/ejgg+QI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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