SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b8fb0ac39b7deeeb9a51710308070d2810ffe862ac4094e02906d16aab8e845' 
  AND token = 'EwTP875KCEwRzg7MoIx5PGjJg8ZDQm8B4mFNzDSM7w0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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