SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '372c9115540620be7109a36e7bc134a31144c067d5ff16526dd05d6437021ec5' 
  AND token = 'xuDddRC2lBletrVOGWSn+zZyy+9IF27ij8eRDATx1bI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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