SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41fa0b9fd37ca82347f661513ed5ec355a0624664eff0f951ca4a63c8db13994' 
  AND token = 'RAzEiOqUihFBjrwktg8PeGXZmz+D+y06wLt6+v53iWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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