SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e65d7fbd116bf98448d4c6329b39124357c3dd2b4c283cb16206b646fab38d3' 
  AND token = 'T2zH294navZgilOM5sNTLtvRmmCE6zw/qrNA3HtYQaU=' 
  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"
    }
  }
}