SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71f64b930c8b386089073ccd0e8cb62fe2486daa532428737b1fda8895a56c2a' 
  AND token = 'SNGrQWpM3w/1HvqaFRw6oOTuCQszgWZSu6u/kdYYiCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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