SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b32237e8735c5687b8898c2f8cfe0d280c7e26cf638d74f8687acd1481bbb14' 
  AND token = 'fuUnspF+jKC2RcgOGYPz5kzWaBUnTQWOCFoZ71rDzY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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