SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'efe21ed71ce41fe5b888f8e6aebeff7ca6cc9e2036211f9c9947e68cdb3da4ef' 
  AND token = 'aT+pAbP2h2pY/GpibbVE5FOKr1TlH+9NEnDacROcblo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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