SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7224907a406d2cb4adca6e27b71de6d61b3bf1997e2a528f476f3ce75a07372' 
  AND token = 'cHkLnl+L8DXpmpjHqVnP1XTZwahF/NVHJVDRM/PpCc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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