SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7b67425dafef5ebbfebee1ee08eac0184994c474c6903719ea4740af92d38f1' 
  AND token = 'ctCMfuWHlX6OeHgY/yVT9xzQBpG80QqLn+akXl7T4Eg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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