SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cfefeb49de34eeebab164fa143e112c75165ec540ebf0355a0dd26dd9031a64' 
  AND token = 'rwKBtFJ7gWTmbvjdmztUdDeWuJzFuuHFH7xFGXN/Y+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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