SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac6f763757d524ee891b4aefd5bcc1e6b05c160c38fbd9ffff11621b1e953486' 
  AND token = 'iA/hjlRahXXGYZdCXSuZlP0U+aNG4WwAvvt6zrdwsaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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