SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30221f0b07a15b9f452da06bfb95393232dc33e5f6e64d899a2730901fcbe768' 
  AND token = 'ECSLhBHY/zhS4rjCZQBvWoIKE8Dj7pHhnZRLGlsPcx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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