SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd8902a8a12819a1f00e6551543b62c20e65db3e9c3b7a75f0015b8fa4858469' 
  AND token = '69yfVWAOQLewIbXfL9l99wv+Y9cM0+WBT2mhF1b7yj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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