SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e61c1070cd78d1374074752d42ba9b1c356f78a027accb20e6185a390841fb0' 
  AND token = 'fFjpqBfwdvkzwA25RosDSGGhDTSYHrtlBcrrGscnUqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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