SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f77792223c76c85ebbaee3e161843949c6a270b3ac3e54380af109107a85151f' 
  AND token = 'QK5XJYKWX5vS21Ruqyaz9nKfBG3OldWpt+Vu+TCD5g0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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