SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb1436a8f5937c9c528d06cfabb36720e792243ab3bbef7f9f1162d3d76f0742' 
  AND token = '988x5EN1/CLN5PnzJg+B9mZ5YLFCE8vWOyVQERvabiM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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