SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c91eb57eb485abb5b8c60a0f5417fd26bba2c300a66fe51d469bc8582d3b129' 
  AND token = 'ropkFLJ35MsnFbcM13WBBlhheJQcqgHkgnFTbF0sgiA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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