SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd83ad84c5fc7ae91b06058f1809589ceb5cf93cce91517c8b59a62897b8b5e33' 
  AND token = '30zGOMMQ/Iy+y8SlQ6VsaKR8hqb4aaDhflxsFzqRvl0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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