SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5604a6d098a9ce941ee0ff046716eb0f98164edb339ad66becffa5a7c47ce7e' 
  AND token = 'zFkwiYFkmJi1lDOClFJAAmBJ8OLLjIWUkT9DAQ3YPTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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