SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59f4070deb2ea8fe82f31a9c0a181c08c776bcb7603151c2974c24642f17262a' 
  AND token = 'UM6qrnCSAm/DY1i8mFaUrKvf7ZZG3dPnjiB7WsyzUek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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