SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89ec49eb428bea61ace968f6e643db936053f454962e527ae99522578d6aafc0' 
  AND token = 'pZlZDZbMgNnIaBu/yBn+ZR+wAG/Jw3SKHMOZsQnmero=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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