SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2aea39c2437df88aa9e5b1d866f836fa825652c52d2383dcc5e44036a571c1d6' 
  AND token = 'FX3ZHXeEtQWuAk6xgkA/MQJDtllfO3x3cgzWy8nI/Zg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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