SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a7bdcdf1b989cf325241852cf8e9395fcd8f59fcfc391c4d417fedb5223eb0b' 
  AND token = 'qTv9KlR1rDGG5owVO97QUTxsvSM6u5TeKIbdJrMpBcI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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