SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98338462e9af726b0f0f231c0bca50cf14ba75c07e9610a4c7f56ec55120ae3d' 
  AND token = 'YkbDEoMVPeYAr/TsR/VgjsmmAXFxSarDCcVAEKvqlvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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