SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '644e77cdcf5a3d2004d6b729441c0357957488e80ee377f5a07dc397c75b8f80' 
  AND token = 'HDTUTwFDFbh2n5HUpuKKOPK1IU2gHJMdUfwDZJz+BQ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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