SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba2e9c7e178cd73c0c6690c2596f3983574c424fa0ef56c8249446e91da03e31' 
  AND token = 'spjksEWV7KeHAx66UF7xVa2UojtvNJH3ZqEQgvx+fvI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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