SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '198d5a9149792e2352989290ce7c28fd18262d03ec5274e319df800a508f6b4b' 
  AND token = 'DzaHcoyskIRWpHAEnZAWaVLYiOC3T9abRuEo9FutU/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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