SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90048daba3e41d57d698ca8535f3d1ec211fe5650258e25608d756e2c46cbf63' 
  AND token = 'iObuYSD0WQq+TH54Nt8GytRIa+nxKn6tF00y99+eik8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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