SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b952199f68ba1b29454c3f90f4d52deed0cd6e02719237e4817f4b578bcc98d8' 
  AND token = 'kZ+wdxz5soY+rOSSR9L5HDBRQg3SQAPBqP0+vmFFxMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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