SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6dd1cefc84c586c1119edce05e01c36817b2345c1a2ac5557b1ab24c950e4372' 
  AND token = 'xsngQlWy1HST7HYt2ouw3Nv/dKQartRNNFzfbS8WRnI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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