SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2106fe03fa68a7c3ed4cebf7545722a7bdefe972e976c444d0d8eb254323670' 
  AND token = 'ntPxZMPG4LDbZjiHs+vgtSXz+EKmVRmNfQkWCmOJRrI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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