SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c485252a5bb2008914dd0f2b57176927254a935e69b8c897086b1294dd971f9f' 
  AND token = '/U9Ivwe7lfmAEDNmvXhZGom/wx9jRgPDQiDkeZzgLgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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