SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7f27147d29e8f3b53bc3b7089b6a999a39e5d28b0cdd742ef832edf5d6c9c6f' 
  AND token = 'LYgHCyM/R9zK1wEf+Ly+HcAYu54J9EqTRCXWENXg+vM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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