SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c4bd594429cdd239166d9cb488d9b5837e3fb1b8445a2877b2821f8f0c75056' 
  AND token = 'isS7rbbiXhXQerT2zBKSh3+URvtGq9jn0aVpuKSwkB4=' 
  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"
    }
  }
}