SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb17e28fc9ad7a76fe6d1363927d3aa7d4593b15f08b904fd186ec4e07bd9ed0' 
  AND token = 'guFqhDW4WZ8bTrL9OrAO6tmEgPqlJt3I7idSpQ1ywjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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