SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7291c4ff68cb8e521e4e0119f8586a1b2e035195766b9f5b659ae4374bda012a' 
  AND token = 'vVdpTLg2pL5yH8QidYMwwKpKihIvP/ihhkuyC0g9njs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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