SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3799a70a5fd361e32be3b59a6b8e64e3d48f76b0fb4c5096ecbad5915324144b' 
  AND token = 'rc9+Pdl/qOV+Y2EVXtFjWqVcje/4zG3EjEVBJJQi+ls=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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