SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb26555b03c73a9a3dae98cf12b46fe453304eded8a96dcc9c83750ad7a8fb4c' 
  AND token = 'JRajULdYLLWzvIqieZyC/u4Z1/7yA7Ss7fYXx0S7u1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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