SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f430f32dd0c694f466b73a5856286767db53ae12f3d9460eaac598063de09a2' 
  AND token = 'PQMp/nrHvnKgLfO+zzBb/1E3wbVFsRAlQU1QdRDh0VY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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