SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09e64f9bbb25c5c8b0d0e22329fdb708366843dba189a68dea73202d1b421942' 
  AND token = 'kw1t3cIgACHWjBdFvwBbDNw4QJNZsEmR1oTi4LHnigk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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