SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9405accc46c25eee4315999f91b8f6d7f961c41f9e861c3eb690ec05113c3c7' 
  AND token = 'fXETi8fGq8TxN+oOkr4DUxbDDmnzgKRsym6pZYfCSek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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