SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87ab5cece47a685de8641d806e34430f7ad6c4f068b7606aef7913477e5d95c1' 
  AND token = 'j6igKW1Qu+EpcdXv+eXL2V8ObyOdJq+4waTqZfxFSyU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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