SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7cac013b95a953730146725a2628b3fb3f23a3026092c5bbf654c8563b3ea553' 
  AND token = 'odiwt4DvxNwqJTqbD9SuniTDIQeuM1dbtA4Yl248c2g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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