SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6443a006232c7207b4d384875a2bb19e90c512bd0ffec2061d0879edafbf48dc' 
  AND token = '+wtX/kS4+0zzkNw0nvlQVyP3qnOHfvaJfkJBEcBYxMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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