SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e6749f704271d57b3dd21c5ea47afff44eabb4eaf884de7207afe23ba00ceb4' 
  AND token = 'MRWxOFrdUNUxEqfe5GfQKdgX33qjekNLccg/GtBGKqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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