SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41df80d877dbcdee804bcb96e226a19b51edf87d6534d800b975154875441d1c' 
  AND token = 'GCbf0pf6uIESM7Na+k0vnn0WuObuULT2txE6Tl0W7I8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}