SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f097bff108eb65adb807a2afef1c41bb1f6c1799fb882bef1063549ac49b5129' 
  AND token = 'euyTMHc5tvjdGLa/Cu5U9BgxVW+GDBdSHkCufDvyeTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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