SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aeb62f550f65bdbb85325232e25ee20842e3cc71cd0c77282dadd9247e528c25' 
  AND token = 'A3H/8QfmYKeFoWPGMtSa+7zvbNzoqbEZMUpwBJIyyhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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