SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ad2d92d1272a6e83f53ef7ccbfadc7728d888b52aaaf1bd894118e9142d4962' 
  AND token = 'gG7UlUlECRI6dHoNNkkq60djm7C4hZ9AY0yO/XJa490=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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