SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4dfd6c1812754a6d82853729458fc6cc4d89421756adcd23a714e59ada92d1b' 
  AND token = 'KtPlE/Osjkm9Pq3PYp1R/JuPvsW1e6XcmdedFpgCxbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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