SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2b8c65c65eaa26e8e65d247df60d5a42f7b6931ade2a43f6787fb8ab0857471' 
  AND token = 'IBmS6Enh4WsTa+Rl9z2mg2F1QsVlFXYD+QfVhVYKnqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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