SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '984fc5663c02715c481989921ddb47dd794672f83a3e84b65808efb87da32035' 
  AND token = 'OrMBBB3MEa2yGlYJZ/txYq+A1gcYqBxrUdQfX+4256w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00102

JSON explain

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