SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77853e51670413304a7006f75e9133363b70655c1fa852231b6fd2b41722e662' 
  AND token = 'Ahr1ogHpgKCYHFs+QNEI4zx/lvux3dzts8YdJPsITpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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