SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c0447fe1587e49672b21444d5636cb49c703e08f2695ffd12e808db79733c3e' 
  AND token = 'JTEAuqvi18nLlOnF8IXRpjFX6HtV/wqlCTBHrYUhOY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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