SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e656f78b37aefdf19dae3fbba15a15ed49b8cc4374e5c71cd568295beed7eb6' 
  AND token = '637QJfvHtrOpAVvD7TFErwTq1vNggTcJqeVi4MR6XWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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