SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96c10c7e1ae48a3939c5edf79251502af55fe50d8dd638ecccbb3f2e59844875' 
  AND token = 'ISFpH3k+6nzopdQkGI65BbxGlSrhZTYE8kWD1d/gHEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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