SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '126ab4109abf6b4d64934759dbcb35136464d74c89367e9d4746baff8f7f2dc0' 
  AND token = '9QXuIpIQLac4AgE1Budt/W7ghFwFZ70zX+OWLBlOf30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}