SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5110651fb72ef5388de820185ef7af7b84565620a5e98d790d0970a0b33fc760' 
  AND token = 'zBElDJZnYFPhNjC6d63H5fBrHASuQI6lkVqVbbeW+9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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