SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '933b894280dbb6530ba872a15c19cfad98a471bd45cb6852fe75c300c6b10af8' 
  AND token = 'jGZS/GK6hmjZLqWhaHjnb8jsrePEFJEuRPmqWD7T+4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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