SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'baa1d9de7d4913977d3c2ae9d0654033125c6b47f8dcd698671f1c6e72e3b002' 
  AND token = '6r51++ckJpHzNXhzaVl8ql0fOHfYeo+r/VBgyh7wsiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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