SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91147d9f2dab00c66eb46f5bdd0dcd153786729d2bcfb35bc449595c22f98817' 
  AND token = 'I4lKqyRkB6OpPL3oMrbNMLCcKy/vvdEsBI7XbntYMrQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00095

JSON explain

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