SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02ef9136b663571e8e82c4385429951a62e41efcedcb906c57145fc13d2f2036' 
  AND token = 'nGI4TBzxRfe1bIyP5XK54QMbmBPSw1j0bAHjs14dAdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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