SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45c4e7de5d2656d44075c4fb41ac819a764751a905d094abf9a9f299097e25a1' 
  AND token = 'EV3/hxmnK6OhSNTtmyJvYKJ04erqdaMmhbhmlL6ao5c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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