SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f3b0ae5bc507b3aca9500ed862d014f1994b3aebb04b38103239bca338fb564' 
  AND token = 'Wx7o9V+IEzR3MZSrnEReDuHRtIrL9RtdL61Mouh3WIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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