SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5726f17d5980da9d5a0f5b133be2a887476298a78951f41cca3feccdac1e9bce' 
  AND token = 'YDwjTus277g+ay/UUM0O6+H3JGgRpV6GAlZTqthN/To=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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