SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f3558d841a3e60b32adf579c7499153d98c41d04c494a4c96791819bce9642e0' 
  AND token = '5HkU+1w4NiiJ05LnuAx7fFZuCnthKN9KdIS/zXgr8X4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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