SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daf371518f7b57502d5ac4f925bef0bab411d332f1cbd79fa18410da2d63d4eb' 
  AND token = 'q6sjKtoOcuMT6TvUU6YbesgPJIRXeklxZ9Sj3SDG+gs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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