SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb3ff8fc88656c107c65bd396c3febf976031a730df9b61c506eadd4b26bdb0e' 
  AND token = '8sqPHlaxrNwNc8OJn3LsjJijvYAWIIteAk1uSvt5xEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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