SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2eb96eb76d621667310c6a6a31a5b8259aeef4c08025129b3b4eccf49bbeb2da' 
  AND token = 'hpdOexYpf9nuOeskitLl8AXuslDBPCZXEgUVOM+iWoY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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