SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2afe6ae202e48444c658f2f0f31522da90d6c0798b594313288464aadda64579' 
  AND token = 'cczFW/olCG+XMELmGA+BWZ1Px/l6Qw0BbI2s5YKK/E8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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