SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce6590800abea6ccc4d0ce6a630fa4d066079da55ab3550fd8b87538f7345838' 
  AND token = 'y5lUgAdewGWwNQGt+82bclMlJGORqLX93MzVMjaQ3tc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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